1. Field of the Invention
The invention relates to front hook eyeglasses to be detachably attached onto eyeglasses body, more particularly to front hook eyeglasses to be simply attached onto the front portion of the eyeglasses body with assurance utilizing at least an elastic force, and a method of attaching the front hook eyeglasses onto the eyeglasses body.
2. Related Art
Not only a mere design but also various high functions have been recently required by eyeglasses.
Eyeglasses are roughly classified into two types, namely, those mounting thereon lenses for correcting eyesight and those mounting lenses for cutting out ultraviolet, (hereinafter referred to as UV cut lenses) (so-called sunglasses).
Since these eyeglasses have to be normally individually used depending on use thereof, it is necessary to prepare the foregoing two types of eyeglasses in the case of avoiding ultraviolet when going out of doors, which is very troublesome.
In view of the foregoing circumstances, eyeglasses having a simple construction and provided with UV cut function in the eyeglasses body, if need be, so-called front hook eyeglasses have been used.
The front hook eyeglasses are very convenient because UV cut lenses of the front hook eyeglasses are easily detachably attached onto the eyeglasses body, if need be.
Meanwhile, as means for attaching the front hook eyeglasses onto the eyeglasses body, there is proposed specific holding means provided in the front hook eyeglasses by way of which the front hook eyeglasses are detachably attached onto the front portion of the eyeglasses body. Most of the holding means comprises clip means for placing the front hook eyeglasses on the front portion or front surface of the eyeglasses body so that the former is caught or supported by the latter.
However, according to the method using the clip means, the front hook eyeglasses are weak relative to a force applied to the right and left directions (toward the direction of the lens surfaces), and is easily displaced from a given position because it slides.
Moreover, a clip of the clipping means is easily bent and an interval between both ends of the clip is liable to be widened (clip is loosened) when the front hook eyeglasses are repeatedly detached from and attached onto the eyeglasses body, causing a problem that a play is produced between the front hook eyeglasses and the eyeglasses body.
If such a problem occurs, it is impossible to fix the front hook eyeglasses to the eyeglasses body with assurance, and the mounting or attaching of the front hook eyeglasses onto the eyeglasses body becomes unstable. Further, when the front hook eyeglasses is repeatedly attached onto the eyeglasses body, there is a possibility that the clip damages the lens surfaces of the eyeglasses body.
Under the circumstances, front hook eyeglasses are developed as disclosed, for example, in Japanese Utility Model Registration No. 3,054 606, which discloses that the front hook eyeglasses are detachably attached onto the front portion of eyeglasses body by means of holding means utilizing a magnetic force.
The front hook eyeglasses have the construction that a pair of first magnetizing means (magnets) are embedded into the lower surface of a bridge of the front hook eyeglasses at portions close to both ends thereof while they are exposed and substantially flush with the surface of the bridge.
A bridge of the eyeglasses body on which the bridge of the front hook eyeglasses (hereinafter referred to front hook bridge) can be mounted has a pair of second magnetizing means (magnets) corresponding to the first magnetizing means embedded into the upper surface of the bridge at portions close to both ends of the upper surface of the bridge while they are exposed and substantially flush with the upper surface of the bridge.
With such construction, the front hook eyeglasses can be attached onto the eyeglasses body with safety by magnetizing between the first and second magnetizing means while the bridge of the front hook bridge is placed on the upper surface of the bridge of the eyeglasses body. Further, even if the front hook eyeglasses are repeatedly detached from or attached onto the eyeglasses body, the lenses of the eyeglasses body are not damaged.
However, according to the conventional method of attaching the front hook eyeglasses onto the eyeglasses body, the front hook eyeglasses are placed on the eyeglasses body by merely magnetizing the first magnetizing means provided on the central portion (front hook bridge) of the former relative to the second magnetizing means provided on the central portion (bridge) of the latter.
The holding of the front hook eyeglasses relative to the eyeglasses body only by a magnetic or magnetizing force does not always secure the attachment therebetween. The reason is that the front hook eyeglasses held by the eyeglasses body are liable to swing about the central portion (front hook bridge) serving as a fulcrum. More in detail, since both ends of the front hook eyeglasses are in a free state where they are not supported by the eyeglasses body, a play is produced in the front and rear sides thereof (vertical direction relative to the surfaces of lenses) and the upper and lower sides thereof (direction of the surfaces of lenses). Accordingly, the state of attachment of the front hook eyeglasses relative to the eyeglasses body is very unstable.
Further, the first and second magnetizing means are respectively provided on narrow regions, namely, the front hook bridge and the bridge of the front hook eyeglasses and eyeglasses body. Although, attachment holes in which magnets are embedded are bored normally by a drill or the like, it requires a high skill and technique to bore the attachment holes in the narrow regions by a given depth.
Still further, boring of the attachment holes in the bridge of the eyeglasses body at two spots (recesses are defined in the bridge) which has to be prevented from being damaged as much as possible is inconvenient in view of external appearance, and also increases manufacturing steps. Further, metal is used and hence it can not be lightweight.
The invention has been developed to solve the foregoing problems of the conventional front hook eyeglasses and the method of attaching the front hook eyeglasses onto the eyeglasses body.
It is therefore an object of the invention to provide front hook eyeglasses which can be attached onto an eyeglasses body with assurance in a stable state without producing a play therebetween and a method of attaching the front hook eyeglasses onto the eyeglasses body.
It is another object of the invention to provide front hook eyeglasses which can be simplified in construction so that the front hook eyeglasses are rendered lightweight and easily manufactured and a method of attaching the front hook eyeglasses onto an eyeglasses body.
Meanwhile, the inventor of this application endeavored himself to study the foregoing problems and has solved the conventional problems by rendering a curvature of front curve of the portion of the front hook eyeglasses large, based on which the invention has been completed.
That is, a method of attaching front hook eyeglasses onto an eyeglasses body according to a first aspect of the invention includes the steps of rendering a curvature of a front curve of the front hook eyeglasses B larger than that of the eyeglasses body A, attaching a central portion of the front hook eyeglasses B onto a central portion of the eyeglasses body A, and bringing both ends of the front hook eyeglasses B into elastic contact with the eyeglasses body A.
A method of attaching front hook eyeglasses B onto an eyeglasses body A according to a second aspect of the invention includes the steps of rendering a curvature of a front curve of the front hook eyeglasses B larger than that of the eyeglasses body A, mutually engaging a bridge of the front hook eyeglasses B with that of the eyeglasses body A, and bringing both ends of the front hook eyeglasses B into elastic contact with the eyeglasses body A.
Front hook eyeglasses B to be attached onto an eyeglasses body A according to a third aspect of the invention include a pair of lenses and a bridge for connecting the pair of lenses thereto, wherein a curvature of the front curve of the front hook eyeglasses B is larger than that of the eyeglasses body A and the bridge of the front hook eyeglasses B is engageable with that of the eyeglasses body A.
The front hook eyeglasses B according to a fourth aspect of the invention is characterized in that the bridge of the front hook eyeglasses B is engageable with that of the eyeglasses body A such that the former is inserted into the latter from the outside of the former.
The front hook eyeglasses B according to a fifth aspect of the invention is characterized in that the bridge of the front hook eyeglasses B is engageable with that of the eyeglasses body A such that the former is inserted into the latter from the outside of the former.
The front hook eyeglasses B according to a sixth aspect of the invention is characterized in that the bridge of the front hook eyeglasses B is engageable with that of the eyeglasses body A such that the former is inserted into the latter from the upper outside of the former.
The front hook eyeglasses B according to a seventh aspect of the invention is characterized in that the bridge of the front hook eyeglasses B is formed of a thermoplastic synthetic resin and both ends of the bridge of the front hook eyeglasses B are inserted into small holes defined in the pair of lenses of the front hook eyeglasses B and are fixed to the pair of lenses by welding.
The front hook eyeglasses B according to an eighth aspect of the invention is characterized in that the bridge of the front hook eyeglasses B is formed of an elastomer and both ends of the bridge of the front hook eyeglasses B are inserted into small holes defined in the pair of lenses of the front hook eyeglasses B and are elastically fixed to the pair of lenses by welding.
Further, it is possible to employ the construction of the combination of not less than a selected two of the foregoing third to eighth aspects of the invention if the combination achieves the objects of the invention.
Inasmuch as the invention has the foregoing construction, the front hook eyeglasses can be attached onto the eyeglasses body with assurance in a stable state without producing a play therebetween.
Still further, since the front hook eyeglasses are simplified in construction, they can be rendered lightweight and manufactured with ease.